within this view a number (eg. 8 or unlimited) of the (existing) tabs from the (existing views) can be inserted here. So for example my 'Favourites' view would include the following tabs:
* Overdue (from due-date view)
* Today (from due-date view)
* Next 7 days (from due-date view)
* Waiting for (one of my Folders)
* Received per mail (one of my custom searches)
* Todos without folder (one of my custom searches)

these are basically the main tabs I use across a day - so having them at hand in one view would same me some time clicking from one to another.

I can imagine the interface to manage this favourites view could be something like this

Please check all the tabs that you would like to have added to your Favourites view:

I like this idea too. You can almost do it today with Advanced Search. But within Advanced Search, you don't get QuickSearch or iPhone access. Having Favorites is nice and frees up Advanced Search for more let's say "advanced" (as opposed to favorite) topics.